docs: def launch_process(self, command):
          # type: (Union[bytes,text_type])->None
          """* What you can do
          - It starts process and keep it.
          """
          if not self.option is None:
              command_plus_option = self.command + " " + self.option
          else:
              command_plus_option = self.command
  
          if six.PY3:
              if shutil.which(command) is None:
                  raise Exception("No command at {}".format(command))
              else:
                  self.process_analyzer = pexpect.spawnu(command_plus_option)
                  self.process_id = self.process_analyzer.pid
          else:
              doc_command_string = "echo '' | {}".format(command)
              command_check = os.system(doc_command_string)
              if not command_check == 0:
                  raise Exception("No command at {}".format(command))
              else:
                  self.process_analyzer = pexpect.spawnu(command_plus_option)
                  self.process_id = self.process_analyzer.pid